Waypoint feet to go vs seconds to go

As I approach most waypoints on a course, the display goes from fractions of a mile to go to the waypoint, then feet to go until it gets to zero.

On some waypoints, however, it changes to seconds to go, from feet to go, then down to zero seconds.

Where is this configured or what is the logic for when it displays feet to go vs.seconds to go. It seems to be on a turn by turn basis. Or something. Maybe just random?